Mendocino County seeking changes at Coyote Dam

The Mendocino County Board of Supervisors is getting ready to send a letter to Congressman Jared Huffman supporting a bill that would compel the U.S. Army Corps of Engineers to rethink the way it runs the Coyote Valley Dam, and how much water can be stored in Lake Mendocino throughout the year.

Huffman last month introduced House of Representatives Bill 3988, called the Fixing Operations of Reservoirs to Encompass Climatic and Atmospheric Science Trends Act, which would let local sponsors of any of the Corps' reservoir projects throughout the nation ask the Corps to find better ways to operate the reservoir in question. The bill would require the Corps to respond and give it three years to do a study.

The ACOE runs the Coyote Valley Dam during flood control season (November through April) using a formula and graph drawn in 1959. Local officials, including the Board of Supervisors, say that doesn't allow Lake Mendocino to store enough water to ensure a steady supply the rest of the year, because the Corps uses that decades-old rule curve to instead release over the dam and down the Russian River any water in the lake that rises above a set flood control limit.

Because of the Corps' old rule curve, drought conditions are now so dire that Lake Mendocino could go dry for the first time since it was built, according to Russian River Flood Control and Water Conservation District General Manager Sean White.

The Corps released about 24,000 acre-feet in January of 2013 to comply with the 55-year-old formula, and, White noted, "it never rained after that." (An acre-foot is the amount of water needed to flood an acre of land under a foot of water.) Since then, Lake Mendocino's level has never risen even as high as the flood control line.

The requirement in the FORECAST Act that the Corps rethink how it runs the dam based on modern science and weather forecasting could have prevented that, the Mendocino County Board of Supervisors argues in its letter of support.

"Had this requirement been in place in January of 2013, what is now critically important water would not have been released because of protocol and the interpretation of operations manuals," the letter states. "Mendocino County is in a state of emergency in some of its areas precisely because of the loss of that additional 24,000 AF (acre-feet).... This is unacceptable."

Lake Mendocino will go dry by September, and possibly earlier if it doesn't get another two inches of rain and 45 percent conservation by all who use its water, inside and outside Mendocino County, according to White.

"If this happens, the regional impacts for all users will be dire," the board's letter states.

The current drought in the Western United States "illuminated the shortcomings of California's water storage and management policies," according to the letter, which goes on to say that some of those problems exist at the federal level.

"One of the most notable policy failures is driven by the Army Corps of Engineers in relation to the operation of reservoirs," the letter states.

The board acknowledges that the Coyote Valley Dam was originally built by the Corps for flood control, but says the water stored behind it "have increasingly been relied upon for domestic environmental and agricultural uses in both Mendocino and Sonoma counties."

Communities in both counties rely on diversions and "significant pumping" of water from the Russian River, the letter says. "Add to that the minimum by-pass flows mandated to support the salmonid species in the river, and you have a very high demand for this water."

If the bill passes and the Corps completes a study on the operation of the Coyote Valley Dam, the Secretary of the Army would then decide whether a change would improve one or more of the Corps' functions, including "reducing risks to human life, public safety and property; reducing the need for future disaster relief; improving local water storage capability and reliability in coordination with the non-federal sponsor and other water users; restoring, protecting or mitigating the impacts of a water resources development project on the environment; or improving fish species habitat or population within the boundaries and downstream of a water resources project," according to the letter.

The letter is dated March 25, the day of the board's next regularly-scheduled meeting.

Tiffany Revelle can be reached at udjtr@ukiahdj.com, on Twitter @TiffanyRevelle or at 468-3523.